{"id":4111,"date":"2024-07-17T16:44:00","date_gmt":"2024-07-17T16:44:00","guid":{"rendered":"https:\/\/www.osmosis.org\/blog\/?p=4111"},"modified":"2025-10-01T11:38:22","modified_gmt":"2025-10-01T19:38:22","slug":"usmle-step-1-question-of-the-day-inheritance-patterns","status":"publish","type":"post","link":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns","title":{"rendered":"USMLE\u00ae Step 1 Question of the Day: Inheritance patterns"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_80 ez-toc-wrap-center counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">In This Article<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns\/#The_correct_answer_to_todays_USMLE%C2%AE_Step_1_Question_is%E2%80%A6\" >The correct answer to today&#8217;s USMLE\u00ae Step 1 Question is&#8230;<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns\/#Incorrect_Answer_Explanations\" >Incorrect Answer Explanations<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns\/#Main_Explanation\" >Main Explanation<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns\/#Major_Takeaway\" >Major Takeaway<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns\/#References\" >References<\/a><\/li><\/ul><\/nav><\/div>\n\n<p class=\"wp-block-paragraph\"><strong><em>Test your knowledge with this USMLE Step 1 Question of the Day. A 3-year-old boy is brought to the office due to difficulty keeping up with other children at daycare. The physical examination reveals enlarged calves, and a genetic condition is suspected. Review the patient&#8217;s family pedigree and determine the most likely inheritance pattern for this condition.<\/em><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A 3-year-old boy is brought to the office by his parents because of difficulty keeping up with other children at daycare. The parents report that he has difficulty climbing stairs and seems more tired and less interested in active play. The patient has a history of upper respiratory tract infections twice in the last year. Temperature is 37\u00b0C (98.6\u00b0F), pulse is 70\/min, respirations are 19\/min and blood pressure is 100\/60 mmHg. Physical examination shows enlarged and nontender calves bilaterally. The rest of the examination is unremarkable. A genetic condition is suspected. The patient\u2019s family pedigree with respect to this condition is shown with the red arrow indicating his position within the family.&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" height=\"833\" width=\"1024\" src=\"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/patients-family-pedigree.png?w=1024\" alt=\"Patient's family tree or pedigree\" class=\"wp-image-4113\" srcset=\"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/patients-family-pedigree.png 1244w, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/patients-family-pedigree.png?resize=300,244 300w, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/patients-family-pedigree.png?resize=768,625 768w, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/patients-family-pedigree.png?resize=1024,833 1024w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Assuming that the genetic condition demonstrates complete penetrance, which of the following inheritance patterns is most likely in this patient?&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>A.&nbsp;X-linked dominant&nbsp;<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>B.&nbsp;X-linked recessive&nbsp;<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>C.&nbsp;Autosomal dominant&nbsp;<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>D.&nbsp;Autosomal recessive&nbsp;<\/strong><strong>E.&nbsp;Mitochondrial&nbsp;<\/strong><\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\"><em>Scroll down for the correct answer!<\/em><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"The_correct_answer_to_todays_USMLE%C2%AE_Step_1_Question_is%E2%80%A6\"><\/span>The correct answer to today&#8217;s USMLE\u00ae Step 1 Question is&#8230;<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>B.\u00a0X-linked recessive\u00a0<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Before we get to the Main Explanation, let&#8217;s look at the incorrect answer explanations. Skip to the bottom if you want to see the correct answer right away!<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Incorrect_Answer_Explanations\"><\/span>Incorrect Answer Explanations<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>A.\u00a0X-linked dominant\u00a0<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Incorrect:<\/strong>&nbsp;In X-linked dominant inheritance, at least one parent (of either sex) is affected.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>C.\u00a0Autosomal dominant\u00a0<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Incorrect:<\/strong>&nbsp;In autosomal dominant inheritance, more than one generation is affected; therefore, at least one parent should also be affected. Both male and females can have the disease.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>D.\u00a0Autosomal recessive\u00a0<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Incorrect:<\/strong>&nbsp;Autosomal recessive conditions usually affect only one generation, and both parents of the affected child should at least be a carrier of the disease. With two carrier parents, only 25% of the children will be affected, and both males and females can be affected by the mutation.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>E.\u00a0Mitochondrial\u00a0<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Incorrect:<\/strong>&nbsp;Diseases that have mitochondrial inheritance are transmitted only by females, and all of the affected female\u2019s offspring are likely to show the signs of the disease.&nbsp;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Main_Explanation\"><\/span>Main Explanation<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The pedigree shows that only&nbsp;males&nbsp;are affected by the disease. Specifically, male offspring of unaffected parents are affected and there is no evidence of&nbsp;male-to-male transmission. This pattern is most likely suggestive of&nbsp;X-linked recessive inheritance&nbsp;from an&nbsp;asymptomatic carrier female&nbsp;in the first generation. In X-linked recessive disease:&nbsp;<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>If the&nbsp;female is a carrier,&nbsp;&nbsp;50%&nbsp;of her&nbsp;sons&nbsp;will end up having the&nbsp;mutation&nbsp;and&nbsp;50%&nbsp;of&nbsp;daughters&nbsp;will be&nbsp;carriers&nbsp;for the mutation.&nbsp;<\/li>\n\n\n\n<li>Affected males&nbsp;will always produce&nbsp;unaffected sons&nbsp;and&nbsp;carrier daughters.&nbsp;<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">This patient is most likely suffering from&nbsp;Duchenne muscular dystrophy&nbsp;(DMD).&nbsp;About 2\/3rds of the time, the affected patient\u2019s mother is a carrier, and the other 1\/3rd of the time the disease is sporadic, which means it is caused by a new mutation. Patients with DMD may experience a gradual and relentless deterioration, and most patients lose ambulation before the age of 12 years. Most patients with DMD die in their 20s or 30s. Therefore, it is important to counsel the parents regarding the risk of having another child with a similar mutation.&nbsp;&nbsp;&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Becker muscular dystrophy&nbsp;(BMD)&nbsp;is similar to DMD but manifests later in life. It is also an&nbsp;X-linked recessive disease.&nbsp;BMD patients typically have a milder clinical course than those with DMD, and remain ambulatory into adult life. They usually survive beyond the age of 30 years and have a mean age of death in the mid-40s.&nbsp;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Major_Takeaway\"><\/span>Major Takeaway<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">In diseases demonstrating an X-linked recessive inheritance, carrier females have 50% chance of producing affected sons and 50% chance of carrier daughters. Furthermore, affected males will always produce unaffected sons and carrier daughters, with no male-to-male transmission. Duchenne and Becker muscular dystrophies are inherited as X-linked recessive disorders.&nbsp;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"References\"><\/span>References<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>&#8220;Muscular Dystrophy: Hope Through Research&#8221;. NINDS. March 4, 2016. Archived from the original on 30 September 2016. Retrieved 12 September 2016.\u00a0<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/www.osmosis.org\/blog\/all-your-usmle-step-1-questions-answered-the-osmosis-ultimate-guide\" target=\"_blank\" rel=\"noreferrer noopener\"><img loading=\"lazy\" decoding=\"async\" width=\"700\" height=\"250\" src=\"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/the-ultimate-guide-usmle-step-1-banner.png?w=700\" alt=\"The Ultimate Guide to the USMLE Step 1: Everything you need to know\" class=\"wp-image-760\" srcset=\"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/the-ultimate-guide-usmle-step-1-banner.png 700w, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/the-ultimate-guide-usmle-step-1-banner.png?resize=300,107 300w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/a><figcaption class=\"wp-element-caption\"><em><em><sub>The United States Medical Licensing Examination (USMLE\u00ae) is a joint program of the Federation of State Medical Boards (FSMB\u00ae) and National Board of Medical Examiners (NBME\u00ae). Osmosis is not affiliated with NBME nor FSMB.&nbsp;<\/sub><\/em><\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><em><strong>Want more USMLE\u00ae Step 1 practice questions? Try Osmosis by Elsevier today! Access your\u00a0<em><strong><a href=\"https:\/\/www.osmosis.org\/login?type=create\" target=\"_blank\" rel=\"noreferrer noopener\">free trial<\/a><\/strong><\/em>\u00a0and find out why millions of current and future clinicians and caregivers love learning with us.<\/strong><\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Test your knowledge with this USMLE Step 1 Question of the Day. A 3-year-old boy is brought to the office due to difficulty keeping up with other children at daycare. The physical examination reveals enlarged calves, and a genetic condition is suspected. Review the patient&#8217;s family pedigree and determine the most likely inheritance pattern for [&hellip;]<\/p>\n","protected":false},"author":202,"featured_media":4112,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[27,20,16,1366,1369,44],"tags":[],"class_list":["post-4111","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-medicine","category-exam-prep","category-do","category-questions","category-step-1-questions","category-step-1"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v23.6 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>USMLE\u00ae Step 1 Question of the Day: Inheritance patterns - Osmosis Blog<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"USMLE\u00ae Step 1 Question of the Day: Inheritance patterns - Osmosis Blog\" \/>\n<meta property=\"og:description\" content=\"Test your knowledge with this USMLE Step 1 Question of the Day. A 3-year-old boy is brought to the office due to difficulty keeping up with other children at daycare. The physical examination reveals enlarged calves, and a genetic condition is suspected. Review the patient&#8217;s family pedigree and determine the most likely inheritance pattern for [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns\" \/>\n<meta property=\"og:site_name\" content=\"Osmosis Blog\" \/>\n<meta property=\"article:published_time\" content=\"2024-07-17T16:44:00+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-10-01T19:38:22+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-inheritance-patterns.webp\" \/>\n\t<meta property=\"og:image:width\" content=\"1080\" \/>\n\t<meta property=\"og:image:height\" content=\"1080\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/webp\" \/>\n<meta name=\"author\" content=\"Marina Horiates Kerekes, MD &amp; Team\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":[\"Article\",\"BlogPosting\"],\"@id\":\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns\"},\"author\":{\"name\":\"Marina Horiates Kerekes, MD &amp; Team\",\"@id\":\"https:\/\/www.osmosis.org\/blog\/#\/schema\/person\/c7e60a94ecf3ec6e6cfe4855957afafc\"},\"headline\":\"USMLE\u00ae Step 1 Question of the Day: Inheritance patterns\",\"datePublished\":\"2024-07-17T16:44:00+00:00\",\"dateModified\":\"2025-10-01T19:38:22+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns\"},\"wordCount\":815,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\/\/www.osmosis.org\/blog\/#organization\"},\"image\":{\"@id\":\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-inheritance-patterns.webp\",\"articleSection\":[\"Allopathic Medicine (MD)\",\"Exam Prep\",\"Osteopathic Medicine (DO)\",\"Questions of the Day\",\"USMLE Step 1\",\"USMLE\u00ae Step 1\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns\",\"url\":\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns\",\"name\":\"USMLE\u00ae Step 1 Question of the Day: Inheritance patterns - Osmosis Blog\",\"isPartOf\":{\"@id\":\"https:\/\/www.osmosis.org\/blog\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#primaryimage\"},\"image\":{\"@id\":\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-inheritance-patterns.webp\",\"datePublished\":\"2024-07-17T16:44:00+00:00\",\"dateModified\":\"2025-10-01T19:38:22+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#primaryimage\",\"url\":\"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-inheritance-patterns.webp\",\"contentUrl\":\"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-inheritance-patterns.webp\",\"width\":1080,\"height\":1080},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.osmosis.org\/blog\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"USMLE\u00ae Step 1 Question of the Day: Inheritance patterns\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.osmosis.org\/blog\/#website\",\"url\":\"https:\/\/www.osmosis.org\/blog\/\",\"name\":\"Osmosis Blog\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\/\/www.osmosis.org\/blog\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.osmosis.org\/blog\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/www.osmosis.org\/blog\/#organization\",\"name\":\"Osmosis Blog\",\"url\":\"https:\/\/www.osmosis.org\/blog\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.osmosis.org\/blog\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/07\/OsmosisElsevierStacked.png\",\"contentUrl\":\"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/07\/OsmosisElsevierStacked.png\",\"width\":1276,\"height\":596,\"caption\":\"Osmosis Blog\"},\"image\":{\"@id\":\"https:\/\/www.osmosis.org\/blog\/#\/schema\/logo\/image\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.osmosis.org\/blog\/#\/schema\/person\/c7e60a94ecf3ec6e6cfe4855957afafc\",\"name\":\"Marina Horiates Kerekes, MD &amp; Team\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.osmosis.org\/blog\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/c4eaddbf095676223204097f8973e0eed2b2b435a8c32f8f6b8c06da77819aa6?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/c4eaddbf095676223204097f8973e0eed2b2b435a8c32f8f6b8c06da77819aa6?s=96&d=mm&r=g\",\"caption\":\"Marina Horiates Kerekes, MD &amp; Team\"},\"description\":\"Authors: Marina Horiates Kerekes, MD &amp; Osmosis Question Writing Team\",\"url\":\"https:\/\/www.osmosis.org\/blog\/author\/marinahoriateskerekesandteam\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"USMLE\u00ae Step 1 Question of the Day: Inheritance patterns - Osmosis Blog","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns","og_locale":"en_US","og_type":"article","og_title":"USMLE\u00ae Step 1 Question of the Day: Inheritance patterns - Osmosis Blog","og_description":"Test your knowledge with this USMLE Step 1 Question of the Day. A 3-year-old boy is brought to the office due to difficulty keeping up with other children at daycare. The physical examination reveals enlarged calves, and a genetic condition is suspected. Review the patient&#8217;s family pedigree and determine the most likely inheritance pattern for [&hellip;]","og_url":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns","og_site_name":"Osmosis Blog","article_published_time":"2024-07-17T16:44:00+00:00","article_modified_time":"2025-10-01T19:38:22+00:00","og_image":[{"width":1080,"height":1080,"url":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-inheritance-patterns.webp","type":"image\/webp"}],"author":"Marina Horiates Kerekes, MD &amp; Team","twitter_card":"summary_large_image","schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":["Article","BlogPosting"],"@id":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#article","isPartOf":{"@id":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns"},"author":{"name":"Marina Horiates Kerekes, MD &amp; Team","@id":"https:\/\/www.osmosis.org\/blog\/#\/schema\/person\/c7e60a94ecf3ec6e6cfe4855957afafc"},"headline":"USMLE\u00ae Step 1 Question of the Day: Inheritance patterns","datePublished":"2024-07-17T16:44:00+00:00","dateModified":"2025-10-01T19:38:22+00:00","mainEntityOfPage":{"@id":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns"},"wordCount":815,"commentCount":0,"publisher":{"@id":"https:\/\/www.osmosis.org\/blog\/#organization"},"image":{"@id":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#primaryimage"},"thumbnailUrl":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-inheritance-patterns.webp","articleSection":["Allopathic Medicine (MD)","Exam Prep","Osteopathic Medicine (DO)","Questions of the Day","USMLE Step 1","USMLE\u00ae Step 1"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns","url":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns","name":"USMLE\u00ae Step 1 Question of the Day: Inheritance patterns - Osmosis Blog","isPartOf":{"@id":"https:\/\/www.osmosis.org\/blog\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#primaryimage"},"image":{"@id":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#primaryimage"},"thumbnailUrl":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-inheritance-patterns.webp","datePublished":"2024-07-17T16:44:00+00:00","dateModified":"2025-10-01T19:38:22+00:00","breadcrumb":{"@id":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#primaryimage","url":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-inheritance-patterns.webp","contentUrl":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-inheritance-patterns.webp","width":1080,"height":1080},{"@type":"BreadcrumbList","@id":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-inheritance-patterns#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.osmosis.org\/blog"},{"@type":"ListItem","position":2,"name":"USMLE\u00ae Step 1 Question of the Day: Inheritance patterns"}]},{"@type":"WebSite","@id":"https:\/\/www.osmosis.org\/blog\/#website","url":"https:\/\/www.osmosis.org\/blog\/","name":"Osmosis Blog","description":"","publisher":{"@id":"https:\/\/www.osmosis.org\/blog\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.osmosis.org\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.osmosis.org\/blog\/#organization","name":"Osmosis Blog","url":"https:\/\/www.osmosis.org\/blog\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.osmosis.org\/blog\/#\/schema\/logo\/image\/","url":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/07\/OsmosisElsevierStacked.png","contentUrl":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/07\/OsmosisElsevierStacked.png","width":1276,"height":596,"caption":"Osmosis Blog"},"image":{"@id":"https:\/\/www.osmosis.org\/blog\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/www.osmosis.org\/blog\/#\/schema\/person\/c7e60a94ecf3ec6e6cfe4855957afafc","name":"Marina Horiates Kerekes, MD &amp; Team","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.osmosis.org\/blog\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/c4eaddbf095676223204097f8973e0eed2b2b435a8c32f8f6b8c06da77819aa6?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/c4eaddbf095676223204097f8973e0eed2b2b435a8c32f8f6b8c06da77819aa6?s=96&d=mm&r=g","caption":"Marina Horiates Kerekes, MD &amp; Team"},"description":"Authors: Marina Horiates Kerekes, MD &amp; Osmosis Question Writing Team","url":"https:\/\/www.osmosis.org\/blog\/author\/marinahoriateskerekesandteam"}]}},"jetpack_featured_media_url":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-inheritance-patterns.webp","jetpack-related-posts":[{"id":1863,"url":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-fragile-x-syndrome","url_meta":{"origin":4111,"position":0},"title":"USMLE\u00ae Step 1 Question of the Day: Fragile X syndrome","author":"Marina Horiates Kerekes, MD &amp; Team","date":"January 3, 2024","format":false,"excerpt":"This week, we are sharing another USMLE\u00ae Step 1-style practice question to test your knowledge of medical topics. Today's case focuses on a 6-year-old adopted boy diagnosed with autism spectrum disorder and Fragile X syndrome. Delve into the discussion with the physician, exploring the family pedigrees that unravel the genetic\u2026","rel":"","context":"In &quot;Allopathic Medicine (MD)&quot;","block_context":{"text":"Allopathic Medicine (MD)","link":"https:\/\/www.osmosis.org\/blog\/category\/medicine"},"img":{"alt_text":"USMLE\u00ae Step 1 Question of the Day: Fragile X syndrome","src":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/68.webp","width":350,"height":200,"srcset":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/68.webp 1x, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/68.webp 1.5x, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/68.webp 2x"},"classes":[]},{"id":755,"url":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-autism-spectrum-disorder","url_meta":{"origin":4111,"position":1},"title":"USMLE\u00ae Step 1 Question of the Day: Autism spectrum disorder","author":"Marina Horiates Kerekes, MD &amp; Team","date":"January 11, 2023","format":false,"excerpt":"This week, we are sharing another USMLE\u00ae Step 1-style practice question to test your knowledge of medical topics.\u00a0Today's case focuses on a 4-year-old-boy who was brought to the pediatrician for evaluation of unusual behavior. Can you figure it out? A 4-year-old boy is brought to the pediatrician for evaluation of\u2026","rel":"","context":"In &quot;Allopathic Medicine (MD)&quot;","block_context":{"text":"Allopathic Medicine (MD)","link":"https:\/\/www.osmosis.org\/blog\/category\/medicine"},"img":{"alt_text":"","src":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/autism-spectrum-disorder.webp","width":350,"height":200,"srcset":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/autism-spectrum-disorder.webp 1x, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/autism-spectrum-disorder.webp 1.5x, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/autism-spectrum-disorder.webp 2x"},"classes":[]},{"id":1621,"url":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-refractive-errors","url_meta":{"origin":4111,"position":2},"title":"USMLE\u00ae Step 1 Question of the Day: Refractive Errors","author":"Marina Horiates Kerekes, MD &amp; Team","date":"September 14, 2022","format":false,"excerpt":"This week, we are sharing another USMLE\u00ae Step 1-style practice question to test your knowledge of medical topics.\u00a0Today's case focuses on a 21-year-old man who has noticed some difficulty reading textbooks or viewing text on his laptop screen.\u00a0Can you figure it out? A 21-year-old man presents to his primary care\u2026","rel":"","context":"In &quot;Allopathic Medicine (MD)&quot;","block_context":{"text":"Allopathic Medicine (MD)","link":"https:\/\/www.osmosis.org\/blog\/category\/medicine"},"img":{"alt_text":"","src":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-refractive-errors.webp","width":350,"height":200,"srcset":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-refractive-errors.webp 1x, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-refractive-errors.webp 1.5x, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/usmle-refractive-errors.webp 2x"},"classes":[]},{"id":1902,"url":"https:\/\/www.osmosis.org\/blog\/usmle-step-2-ck-question-of-the-day-routes-of-infection","url_meta":{"origin":4111,"position":3},"title":"USMLE\u00ae Step 2 CK Question of the Day: Routes of infection","author":"Marina Horiates Kerekes, MD &amp; Team","date":"January 14, 2023","format":false,"excerpt":"Prep for the USMLE\u00ae Step 2 CK exam with today's question focused on a 5-year-old boy presenting with a retropharyngeal abscess. Learn to identify the anatomical boundaries of the \"danger space\" and understand the urgency of managing such infections. Strengthen your clinical knowledge and improve your diagnostic skills for effective\u2026","rel":"","context":"In &quot;Allopathic Medicine (MD)&quot;","block_context":{"text":"Allopathic Medicine (MD)","link":"https:\/\/www.osmosis.org\/blog\/category\/medicine"},"img":{"alt_text":"USMLE Step 2 CK Question of the Day Routes of infection","src":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/71.webp","width":350,"height":200,"srcset":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/71.webp 1x, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/71.webp 1.5x, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/71.webp 2x"},"classes":[]},{"id":3527,"url":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-pyruvate-dehydrogenase-complex","url_meta":{"origin":4111,"position":4},"title":"USMLE\u00ae Step 1 Question of the Day: Pyruvate dehydrogenase complex","author":"Marina Horiates Kerekes, MD &amp; Team","date":"June 21, 2023","format":false,"excerpt":"This week, we are sharing another USMLE\u00ae Step 1-style practice question to test your knowledge of medical topics.\u00a0Today's case focuses on a 6-month-old male infant who is brought to the pediatrician for evaluation of poor weight gain. The patient was born at 38-weeks gestational age via an uncomplicated vaginal delivery.\u2026","rel":"","context":"In &quot;Allopathic Medicine (MD)&quot;","block_context":{"text":"Allopathic Medicine (MD)","link":"https:\/\/www.osmosis.org\/blog\/category\/medicine"},"img":{"alt_text":"","src":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/umsle-pyruvate-dehydrogenase-complex.webp","width":350,"height":200,"srcset":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/umsle-pyruvate-dehydrogenase-complex.webp 1x, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/umsle-pyruvate-dehydrogenase-complex.webp 1.5x, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/umsle-pyruvate-dehydrogenase-complex.webp 2x"},"classes":[]},{"id":1969,"url":"https:\/\/www.osmosis.org\/blog\/usmle-step-1-question-of-the-day-zenkers-diverticulum","url_meta":{"origin":4111,"position":5},"title":"USMLE\u00ae Step 1 Question of the Day: Zenker&#8217;s Diverticulum","author":"Marina Horiates Kerekes, MD &amp; Team","date":"April 14, 2021","format":false,"excerpt":"Each week, Osmosis shares a USMLE\u00ae Step 1-style practice question to test your knowledge of medical topics. Today's case involves an 80-year-old man. He was hospitalized two weeks ago for pneumonia and now reports difficulty swallowing and regurgitation of undigested food particles.\u00a0 Can you figure out the diagnosis and which\u2026","rel":"","context":"In &quot;Allopathic Medicine (MD)&quot;","block_context":{"text":"Allopathic Medicine (MD)","link":"https:\/\/www.osmosis.org\/blog\/category\/medicine"},"img":{"alt_text":"","src":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/80.webp","width":350,"height":200,"srcset":"https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/80.webp 1x, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/80.webp 1.5x, https:\/\/www.osmosis.org\/blog\/wp-content\/uploads\/sites\/2\/2024\/09\/80.webp 2x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.osmosis.org\/blog\/wp-json\/wp\/v2\/posts\/4111","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.osmosis.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.osmosis.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.osmosis.org\/blog\/wp-json\/wp\/v2\/users\/202"}],"replies":[{"embeddable":true,"href":"https:\/\/www.osmosis.org\/blog\/wp-json\/wp\/v2\/comments?post=4111"}],"version-history":[{"count":3,"href":"https:\/\/www.osmosis.org\/blog\/wp-json\/wp\/v2\/posts\/4111\/revisions"}],"predecessor-version":[{"id":7604,"href":"https:\/\/www.osmosis.org\/blog\/wp-json\/wp\/v2\/posts\/4111\/revisions\/7604"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.osmosis.org\/blog\/wp-json\/wp\/v2\/media\/4112"}],"wp:attachment":[{"href":"https:\/\/www.osmosis.org\/blog\/wp-json\/wp\/v2\/media?parent=4111"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.osmosis.org\/blog\/wp-json\/wp\/v2\/categories?post=4111"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.osmosis.org\/blog\/wp-json\/wp\/v2\/tags?post=4111"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}